Modeling Auxin Transport and Plant Development
The plant hormone auxin plays a critical role in plant development. Central to its function is its distribution in plant tissues, which is, in turn, largely shaped by intercellular polar transport processes. Auxin transport relies on diffusive uptake as well as carrier-mediated transport via influx and efflux carriers. Mathematical models have been used to both refine our theoretical understanding of these processes and to test new hypotheses regarding the localization of efflux carriers to understand auxin patterning at the tissue level. Here we review models for auxin transport and how they have been applied to patterning processes, including the elaboration of plant vasculature and primordium positioning. Second, we investigate the possible role of auxin influx carriers such as AUX1 in patterning auxin in the shoot meristem. We find that AUX1 and its relatives are likely to play a crucial role in maintaining high auxin levels in the meristem epidermis. We also show that auxin influx carriers may play an important role in stabilizing auxin distribution patterns generated by auxin-gradient type models for phyllotaxis.
KeywordsAuxin Phyllotaxis Meristem Arabidopsis Pattern formation AUX1 PINFORMED1 Development
We thank Eric Mjolsness, Elliot M. Meyerowitz, Adrienne Roeder, and Bruce Shapiro for helpful discussions. H.J. acknowledge support from the Swedish Research Council and Human Frontier Science Program. M.G.H. was supported by the National Science Foundation’s Frontiers in Biological Research (FIBR) program, award number EF-0330786; and Department of Energy grant DOE FG02-88ER13873.
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